Document FR-A-2 424 733 INSERM discloses an ultrasound intracorporeal probe that is inserted into the esophagus to measure the flow rate in the aorta. That prior probe is characterized by a catheter structure whose distal portion has a bag that can be inflated from the outside with a liquid and that surrounds the ultrasound emitter which is housed entirely inside the bag which serves to prevent the emitter from moving inside the duct and which serves to couple the emitter acoustically. The emitter is mounted to rotate inside said inflatable bag on a support block which is disposed substantially on the longitudinal axis of the probe, and it is rotated by a flexible cable connected at its proximal end at the outside to rotary drive means, e.g. in the form of a knob (see the claims and the corresponding text describing the figures, in particular page 2, line 24 to page 4, line 29).
That prior INSERM document has been improved in the context of document U.S. Pat. No. 5,479,928 according to which the intracorporeal probe has in combination: at least one broad-beam ultrasound transducer fixed on the support block in such a manner as to be oriented at an angle of inclination that is not perpendicular relative to the longitudinal axis of the probe; and at least one narrow beam ultrasound transducer fixed on the support block so as to be oriented at an angle that is essentially perpendicular relative to the longitudinal axis of the probe so as to be oriented substantially perpendicularly relative to the longitudinal axis of a duct in which the speed of a liquid is to be measured, and in particular the flow rate of the liquid, specifically the flow rate of blood when the duct is a blood vessel.
The improvement according to that document is entirely satisfactory and is available on the market from SOMETEC under the trade name DYNEMO 3000®.